Taken from the Eye of the North manual:
"Fleshreavers are horrible, fleshy monsters with an unusual method of evolution. A young fleshreaver is born as barely more than a small skeleton; the parents assure the survival of their young by layering muscle, tissue and flesh over the delicate newborn. Sewn together by older fleshreavers, they use only the finest musculature and bone from prey to flesh out the body and wings of their young, carving horns from discarded bone fragments. Once a fledging fleshreaver has been fully created, it must continue the handiwork of its parents, acquiring new flesh pieces and better musculature to attach to its skeletal structure in order to supplant its rapidly growing form."
- Despite the undead appearance caused by their unusual habits, Fleshreavers are Fleshy and do not take double Holy damage.